Capitalize “Universal Time” in documentation

It’s a proper noun.
* lisp/vc/add-log.el (add-log-time-zone-rule): Also, fix typo by
mentioning ‘format-time-string’ instead of ‘set-time-zone-rule’.

lisp/calendar/solar.el

@@ -173,7 +173,7 @@ delta.  At present, delta = 0.01 degrees, so the value of the variable
 ;;; End of user options.
 
 (defvar solar-sidereal-time-greenwich-midnight nil
-  "Sidereal time at Greenwich at midnight (universal time).")
+  "Sidereal time at Greenwich at midnight (Universal Time).")
 
 (defvar solar-northern-spring-or-summer-season nil
   "Non-nil if northern spring or summer and nil otherwise.
@@ -413,8 +413,8 @@ Result is in days.  For the years 1800-1987, the maximum error is
 (defun solar-ephemeris-time (time)
   "Ephemeris Time at moment TIME.
 TIME is a pair with the first component being the number of Julian centuries
-elapsed at 0 Universal Time, and the second component being the universal
+elapsed at 0 Universal Time, and the second component counting Universal Time
-time.  For instance, the pair corresponding to November 28, 1995 at 16 UT is
+hours.  For instance, the pair corresponding to November 28, 1995 at 16 UT is
 \(-0.040945 16), -0.040945 being the number of Julian centuries elapsed between
 Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
 
@@ -430,7 +430,7 @@ Result is in Julian centuries of ephemeris time."
   "Right ascension (in hours) and declination (in degrees) of the sun at TIME.
 TIME is a pair with the first component being the number of
 Julian centuries elapsed at 0 Universal Time, and the second
-component being the universal time.  For instance, the pair
+component counting Universal Time hours.  For instance, the pair
 corresponding to November 28, 1995 at 16 UT is (-0.040945 16),
 -0.040945 being the number of Julian centuries elapsed between
 Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.  SUNRISE-FLAG is passed
@@ -444,7 +444,7 @@ to `solar-ecliptic-coordinates'."
   "Azimuth and height of the sun at TIME, LATITUDE, and LONGITUDE.
 TIME is a pair with the first component being the number of
 Julian centuries elapsed at 0 Universal Time, and the second
-component being the universal time.  For instance, the pair
+component counting Universal Time hours.  For instance, the pair
 corresponding to November 28, 1995 at 16 UT is (-0.040945 16),
 -0.040945 being the number of Julian centuries elapsed between
 Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.  SUNRISE-FLAG
@@ -476,8 +476,8 @@ Sunrise if DIRECTION =-1 or sunset if =1 at LATITUDE, LONGITUDE, with midday
 being TIME.
 
 TIME is a pair with the first component being the number of Julian centuries
-elapsed at 0 Universal Time, and the second component being the universal
+elapsed at 0 Universal Time, and the second component counting Universal Time
-time.  For instance, the pair corresponding to November 28, 1995 at 16 UT is
+hours.  For instance, the pair corresponding to November 28, 1995 at 16 UT is
 \(-0.040945 16), -0.040945 being the number of Julian centuries elapsed between
 Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
 
@@ -522,8 +522,8 @@ Uses binary search."
 Parameters are the midday TIME and the LATITUDE, LONGITUDE of the location.
 
 TIME is a pair with the first component being the number of Julian centuries
-elapsed at 0 Universal Time, and the second component being the universal
+elapsed at 0 Universal Time, and the second component counting Universal Time
-time.  For instance, the pair corresponding to November 28, 1995 at 16 UT is
+hours.  For instance, the pair corresponding to November 28, 1995 at 16 UT is
 \(-0.040945 16), -0.040945 being the number of Julian centuries elapsed between
 Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
 

lisp/gnus/gnus-art.el

@@ -1028,7 +1028,7 @@ on parts -- for instance, adding Vcard info to a database."
 
 (defcustom gnus-article-date-headers '(combined-lapsed)
   "A list of Date header formats to display.
-Valid formats are `ut' (universal time), `local' (local time
+Valid formats are `ut' (Universal Time), `local' (local time
 zone), `english' (readable English), `lapsed' (elapsed time),
 `combined-lapsed' (both the original date and the elapsed time),
 `original' (the original date header), `iso8601' (ISO8601

lisp/vc/add-log.el

@@ -575,10 +575,9 @@ Compatibility function for \\[next-error] invocations."
 ;; called add-log-time-zone-rule since it's only used from add-log-* code.
 (defvaralias 'change-log-time-zone-rule 'add-log-time-zone-rule)
 (defvar add-log-time-zone-rule nil
-  "Time zone used for calculating change log time stamps.
+  "Time zone rule used for calculating change log time stamps.
-It takes the same format as the TZ argument of `set-time-zone-rule'.
+If nil, use local time.  If t, use Universal Time.
-If nil, use local time.
+If a string, interpret as the ZONE argument of `format-time-string'.")
-If t, use universal time.")
 (put 'add-log-time-zone-rule 'safe-local-variable
      (lambda (x) (or (booleanp x) (stringp x))))